That is not so much a Perl-question as one related to finding an algorithm, but still very interesting.

My take on that would be:

  1. Calculate the average of the whole list: if you are near the average, you're done; if not, go to step 2.
  2. Calculate how much bytes you must "gain" or "loose" to reach the average and find a file which is as close as possible to that figure and eliminate that file (to "gain" bytes on your average you must eliminate a file with less bytes than your average, so the average increases). Note: to calculate the "new" average, remember that you now have one less file in your list! After eliminating that file, call the new list your "whole" file and feed it to step 1.

For sure this algorithm is not guaranteed to provide a solution, but provided your list is big enough and the lengths of the files are sufficiently well spread out, it should not be too bad (for various appropriate definitions of "big enough", "sufficiently" and "not too bad").

CountZero

A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

In reply to Re: Creating a sub-list constrained by an average while maintaining maximum number of original elements by CountZero
in thread Creating a sub-list constrained by an average while maintaining maximum number of original elements by Jack B. Nymbol

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